What does this mean - flashing -0 on startup

[kentiiboii]

Means your car is due a service. To reset it, turn the ignition off, hold the button in, turn ignition on, wait for countdown to finish, the switch ignition off and on again.

Thats all there is too it???
Can you just do it from cold or does it need to run first??

"Hold button in, turn ignition on, wait for countdown to finish, the switch ignition off and on again.

I couldn't get it to work last time, but think it was more complex.

Yeah thats it. Nothing else. I never bother really as I know when I needs servicing